Server systems

ABSTRACT

The present invention comprises a system for the control of multiple remote resources. A plurality of user stations, each comprising a keyboard, video screen and a mouse, communicate with a server management unit. The server management unit is comprised of a server chassis, matrix switch and a switch server. Remote resources are each connected to a port of a multiplexer or to a server interface. A user station connects to a remote resource by making a request to the server management unit. The switch server identifies the multiplexer or server interface port to which the resource is connected from a database. A request is made to a remote interface server connected to the multiplexer and server interfaces and the remote interface server connects the appropriate ports of the server management unit and the multiplexer or server interface.

This invention relates to the control of computer systems with multipleresources, for example multiple servers.

There are many client/server systems which make use of a large number ofservers; for example Internet Service providers, data warehouses, andsoftware development laboratories. The management, control andmaintenance of such multi-server systems can be complex and expensive.

One known arrangement is our FreeVision™ system, which is the subject ofWO99/22294. This system enables workstations consisting only of videoscreen, keyboard and mouse to be connected to control any selectedserver using only serial signals over category 5 cabling. This systemoffers considerable advantages, but can only be used where the serversare capable of producing and handling keyboard-video-mouse (KVM)signals. One object of the present invention is to enable the provisionof a system in which a user work station can communicate with andcontrol any selected one of a number of “headless” servers which do notthemselves provide video format signals.

More generally, the present invention is concerned with enabling a useroperating in one format to communicate with a resource (which may be aserver or another machine, or a software resource such as a database)operating in another format in a manner which is automatic andtransparent to the user.

Accordingly, the present invention provides a data processing systemincluding one or more user stations each capable of sending andreceiving data in a first form; a plurality of resources each capable ofsending and receiving data in a second form; at least one helpercomputer arranged to transform data between the first and second forms;and a multiplexer for connecting the helper computer, or one of thehelper computers, between a user and a selected resource.

From another aspect, the invention provides a method of operating a dataprocessing system, which system comprises one or more user stations eachcapable of sending and receiving data in a first form and a plurality ofresources each capable of sending and receiving data in a second form;the method comprising:

-   -   detecting a request from a user station requesting the        establishment of a connection with a desired resource;    -   establishing a connection between the user station and a helper        computer; and    -   establishing a connection between the helper computer and the        desired resource;    -   the helper computer being programmed to transform data between        the first and second forms.

Preferred features and advantages of the invention will-be apparent fromthe following description and claims.

An embodiment of the invention will now be described, by way of exampleonly, with reference to the drawing, in which

FIG. 1 is a schematic block diagram of one system in accordance with theinvention.

Referring to FIG. 1, the system includes a number of servers, nine ofwhich are shown at 10. In practice, the system may include severalhundred or more servers. The system also includes a number of userstations, one of which is shown at 12. In practice, there might be sometens of users. Each user station comprises a keyboard, a video screen,and a mouse, each of which communicates with an interface 20. Theinterface 20 permits keyboard-video-mouse (KVM) signals to pass to andfrom the user 10 via a path 22 using the FreeVision™ protocol.

It is desired to enable any user 12 to be connected with any server 10in such a way that the user controls the selected server as though itskeyboard, video screen and mouse were physically connected direct to theserver. In this example, the servers 10 do not produce video signals ina displayable format such as VGA. The invention is based on interposinga helper computer between the user and the selected server to emulatethe missing functions. It would, however, be unnecessarily complex andexpensive to provide a computer for each server, or for each workstation, and therefore a limited number of helper computers (which couldbe one, but will typically be single figures) is incorporated in thesystem so as to be efficiently used, as will now be explained.

Each of the servers 10 is connected to a respective port of a serialmultiplexer (mux) 28. The serial mux 28 in this example is a fullynon-blocking 16-to-many serial mux. It must be able to switch any serialport to any TCP/IP session. Suitable multiplexers to meet these criteriaare well known in the art. Also connected to the serial mux 28 are anumber of helper PCs, two of which are shown at 30, which in turn areconnected to a server interface card 32.

The users 12 are connected via a user interface card 24 to a servermanagement system (SMS) which consists of a switch formed by a matrixswitch 27 and a server chassis 34, a switch server 26, and an SQLdatabase 29 for the switch server 26.

The matrix switch 27 enables a given user port on the user interfacecard 24 to communicate with a given server port on the server interfacecard 32.

Matrix switches of this nature are known per se, and are available forexample from CCC Network Systems of Farnborough, Hants, England andBelfast, Northern Ireland. The matrix switch 27 is similar to thatdescribed in WO99/22294.

The switch server 26 is also arranged to communicate by an appropriateprotocol, in this embodiment TCP/IP, with the helper PCs 30 and with theserial mux's 28.

In a practical embodiment, there may be a large number of mux's such as28, each of which will have up to 16 servers connected to it, and canhave any of a number of PCs connected via TCP/IP.

When a user requests access to a particular server, the followingsequence of events will be performed:

-   (1) The switch server 26 identifies from the database 29 the mux 28    to which the requested server is connected.-   (2) The switch server 26 then makes a request for connection.-   (3) According to the availability of each PC, the system attempts to    propagate the request to any PC in the pool of PCs.-   (4) Once a free PC has identified itself, the switch server 26    instructs the PC which mux and port to connect to, which connects    the appropriate corns ports (provided not in use).-   (5) The selected PC is instructed to start a terminal session with a    shell command, which may usefully be stored as a string in the    database 29.-   (6) The PC confirms successful command execution, and the switch    server 26 connects the user via the user interface card 24, the    switch 27, 34, and the appropriate port of the server interface card    32.

To allow communication with the switch server 26, and to enable requeststo be propagated amongst the PCs, each of the PCs contains an Ethernetcard (or similar networking arrangement). Each PC also has socketlistening software to accept requests from the SMS and to allowtermination of the session at any time. Upon termination, all links canbe broken.

The arrangement described with each PC returning its location or IDallows any number of helper PCs to be connected to the mux. A smallernumber of PCs reduces cost and complexity, while a higher numberminimises blocking. Expansion is simple, merely requiring an additionalPC and additional data in the database. Any PC can connect to any muxvia TCP/IP. Thus there is a flexible pool of resources.

The system as thus far described therefore enables any user to beconnected to any desired server via a helper PC. The servers 10 in thisembodiment are headless servers which do not provide formatted videosignals and may not be organised to accept keyboard and mouse signalsdirectly. The helper PC is therefore provided with terminal emulatorsoftware, so that the combination of the user workstation 12 and theterminal emulator acts as a fully featured terminal to control theselected server.

FIG. 1 also shows a server 110 which is capable of handling KVM signals,to illustrate that this can be connected directly to a port of theserver interface card 34 without the intervention of a helper PC.

In the embodiment shown, the pathways labelled “KVM” carry KVM signalsin analogue format. Other channels as shown operate in RS232. In a largesystem, this greatly simplifies cabling arrangements. However, otherdata transfer protocols may be used.

Our present preference is to use Linux as the PC operating system, asthis avoids licensing restrictions and a large number of Unix terminalemulator programs are freely available. However, this preference isessentially commercial, and it will be appreciated that a wide choice ofoperating systems and emulator software would be suitable.

Thus, the PC and its installed software enable the user to interfacewith the server by proxy, and the PC may be referred to as a “proxyhelper”. The same basic technique may be used to allow interfacing byproxy with resources other than servers, “resource” in this contextbeing used to mean any machine or database. The proxy helpers could, forexample, contain web browsers to interact with web-enabled devices, orcustom interfacing software to interact with, for example, airconditioning systems or alarms. The switch server will know from itsdatabase the type of resource the user requires access to and will usethis information to identify a suitable proxy helper PC from its pool.

In the prior art system of WO99/22294 the helper PC acts as a computerdedicated to navigation of a large multi-user computer system. The userinvokes the helper PC, identifies a list of computers he requires accessto (known as a profile), and then leaves the helper PC. At this point,the switch server takes over control and allows the user to move betweenthe computers in his profile with no further helper PC involvement.Thus, the prior art system is intentionally invoked by the user, and isused temporarily to create or modify a profile.

In the present invention, the user does not intentionally invoke theproxy helper; this is an automatic action performed by the switch serverbased on the type of resource the user wishes to interact with. Proxyhelpers are allocated on a per-session basis. Thus, the proxy helpersare intelligently utilised by the switch server based on resource type,and the operation is transparent to the user.

The system as described is very flexible and may readily be expanded andaltered without requiring much if anything in the way of specialisedhardware or software.

1-15. (canceled)
 16. A data processing system comprising: at least oneuser station; a plurality of resources; at least one remote interfaceserver; and a multiplexer for connecting said remote interface serverbetween said user station and a selected resource.
 17. A systemaccording to claim 16, wherein said user station is capable of sendingand receiving data in a first form.
 18. A system according to claim 17,wherein said resources are capable of sending and receiving data in asecond form.
 19. A system according to claim 18, wherein said remoteinterface server converts data between said first and said second forms.20. A system according to claim 16, including a management unit operableto respond to requests from said user station to establish a connectionfrom said user station to a selected one of said resources via saidremote interface server and said multiplexer.
 21. A system according toclaim 20, wherein said management unit communicates by a networkprotocol.
 22. A system according to claim 20, wherein more than oneremote interface server is connected to network protocol connections,said network protocol connections being connected to said multiplexer.23. A system according to claim 22, wherein said remote interfaceservers communicate using a network protocol.
 24. A system according toclaim 16, wherein said multiplexer comprises a non-blocking switcharrangement.
 25. A system according to claim 24, wherein saidnon-blocking switch arrangement is a matrix switch.
 26. A systemaccording to claim 25, wherein said matrix switch is controlled by aswitch server in accordance with data stored in a database.
 27. A systemaccording to claim 16, wherein said resources are servers.
 28. A systemaccording to claim 27, wherein said servers are headless servers.
 29. Asystem according to claim 28, wherein said remote interface server isloaded with software for use with said headless servers.
 30. A systemaccording to claim 29, wherein said software comprises terminalemulation programs.
 31. A system according to claim 29, wherein saidsoftware comprises a web browser.
 32. A data processing systemcomprising: one or more user interfaces, each capable of sending andreceiving data in a first form; a plurality of remote devices capable ofsending and receiving data in a second form; at least one interfaceserver for converting data from said first form to said second form; anda multiplexer for connecting said interface server between said userinterface and said remote devices.
 33. A system according to claim 32,including a management unit operable to respond to requests from saiduser interface to establish a connection from said user interface to aselected one of said devices via said remote interface server and saidmultiplexer.
 34. A system according to claim 33, wherein said managementunit communicates by a network protocol.
 35. A system according to claim33, wherein more than one interface server is connected to networkprotocol connections, said network protocol connections being connectedto said multiplexer.
 36. A system according to claim 35, wherein saidinterface servers communicate using a network protocol.
 37. A systemaccording to claim 32, wherein said multiplexer comprises a non-blockingswitch arrangement.
 38. A system according to claim 37, wherein saidnon-blocking switch arrangement is a matrix switch.
 39. A systemaccording to claim 38, wherein said matrix switch is controlled by aswitch server in accordance with data stored in a database.
 40. A systemaccording to claim 32, wherein said remote devices are servers.
 41. Asystem according to 40, wherein said servers are headless servers.
 42. Asystem according to claim 41, wherein said interface server is loadedwith software for use with said headless servers.
 43. A system accordingto claim 42, wherein said software comprises terminal emulationprograms.
 44. A system according to claim 42, wherein said softwarecomprises a web browser.
 45. A method for operating a data processingsystem, said system comprising one or more user stations capable ofsending and receiving data in a first form and a plurality of resourcescapable of sending and receiving data in a second form, said methodcomprising the steps of: detecting a request from a first user stationrequesting establishment of communication with a first resource;establishing a first connection between said first user station and aremote interface server; and establishing a second connection betweensaid remote interface server and said first resource wherein said remoteinterface server receives data from said user station and said firstresource; and wherein said remote interface server is configured toconvert data between said first form and said second form.
 46. A methodaccording to claim 45, wherein said remote interface server is selectedfrom a plurality of remote interface servers.
 47. A method according toclaim 46, wherein said first connection is via a matrix switch.
 48. Amethod according to claim 47, wherein said second connection is via amultiplexed network containing said resources and said plurality ofremote interface servers.